Telescopic hoisting boom



Feb. 9, 1954 c. B. GARLAND 2,668,625

TELESCOPIC HOISTING BOOM v Filed Jan. 9, 1953 3 Sheets-Sheet 1 u 9i 34INVENTOR.

' CLnUaE 62mm/v0 BY a A.

V Y l Feb. 9, 1954 c. B. GARLAND TELESCOPIC HOISTING BOOM 3 Sheets-Sheet2 Filed Jan. 9, 1953 INVENTOR lCLAN/01:79. 6mm/vo Feb. 9, 1954 c. B.GARLAND TELESCOPIC HOISTING BOOM 3 Sheets-Sheet 3 Filed Jan. 9, 195:5

JNVEN'TQR. CLAUDE 62mm/v0 Patented Feb. 9, 1954 vUNITED STATES ?ATENTOFFICE TELESGOPIO HOISTING VBOOM Application January 9, 1953, Serial No.330,516

6 Claims. 1

This .invention relates generally to telescopic truckfmounted booms forlight hoisting, .of the general type Ydisclosed in Amy prior Patent No.2,571,858.

Briefly described, such a .boom comprises a plurality oi. telescopicallyarranged tubes, of pro gressively smaller diameter, the larger tubebeing 'mounted for pivotal action about horizontal and vertical axes,and there being provided cable and pulley arrangements for extendingeach tube from the .next 'larger or lower tube, in such arrangement thatall of the -tubes can be extended simultaneously from a compact fullytelescoped carrying position to a partially or fully extended operatingposition. Each tube is suiiiciently smaller 'in diameter than `thepreceding tube .to accommodate these cable and pulley arrangements, ,andin a preferred embodiment, the tubes are placed in eccentric positionswithin one another so as to provide a maximum of space for the cables.With the latter arrangement, the dilerence in diameter from tube to tubenecessary to .accommodate the cables is minimized, and the diameter ofthe largest tube of the series need not be overly large, nor thediameter of the smallesttube undesirably small.

A general object of the present invention is the provision of such atelescopic, extensible boom having increased .cable strength for heavyduty service. Obviously, for additional cable strength, a larger cablemight be employed, but a cable larger than is now bei-ng used in thistype of equipment becomes stili `and unwieldy, and cannot easily bethreaded and pulled around pulleys and guides of the largest sizes thatcan easily .be :used in .such an apparatus. Obviously also, y.additionalcables could be employed, simply in duplication `of those arranged as inmy prior patent, but unless the multiple cables are made of precisely.the same length-Fa condition virtually impossible .of achievement inpractice.- only Ithe shorter cable would carry the load, and anyslightly longer cable would remain slack and of no advantage beyondstand-by service, to as sume lthe load in the event that the rst cableshould part.

Accordingly a more specic Vobject :is the pro. visionof :a multiplecable arrangement, with pro'- vislon for equalization .of theloadbetween the several cable nights or courses.

VAccording to the invention, multiple cable flights .or .courses areformed from single cables, with successi-ve courses looped aboutequalizing guides, so that `the loads assumed by the several courses areautomatically equalized. The inven tion consists lin the cable, pulleyand equalizing guide arrangements 'by which .this advantage is achieved,

The `invention will be more fully understood from the following detaileddescription of one .2 present illustrative .embodiment thereof,reference .rior this purpose being had to .the accompanying drawings, inwhich:

`Figure 1 is a side elevational view of a boom in Aaccordance with vthepresent invention mounted in a .conventional manner on the platform .ofa carrying truck;

Figure 2 is a fragmentary perspective view of the lower end portion .ofthe boom of .the inven. tion;

'Figure 3 is -a transverse section taken on line 3-3 .of 'Figure l;

Figure 4 is a plan View of a portion of the boom, taken .as indicated.by the arrow 4 in Figure 3;

Figure .5 is fa perspective view `of a bearing;

Figure .5 is a longitudinal sectional view of the boom of the invention,the plane of the section being adjusted to .pass through pulley housingsat the ends `of the several tube sections as indi.- cated zby the arrows6 in Figures 3, '7 and .8;

Figure 7 is Aa transverse section as taken on line 1 7 of Figure 1;

Figure 8 is a .transverse section taken as indicated by line 8--8 .ofAFigure 1;

Figure .9 ,is `a perspective view of the rearward end or" one of thetelescopic boom sections;

.Figure 1 0 is :a perspective vview of the rearward end portion .of thenext smaller telescopic boom section "Figure 11 is a diagrammatic viewin perspective showing schematically the `cable and pulley arrangement`of the boom of the present invention:

Figure 12 is la transverse section taken as indicated by the line i2l2of Figure 10;

Figure 13 is a perspective .of a pulley housing and cable guide andclamping means on the outer end or" the first Aboom section;

.Figure 14 shows a modied pulley and cable arrangement; and

Figure Y15 lis a vtransverse section taken as indicated .by .arrowslea-...i5 of vliigure 1.4.

As shown in Figure 1, the boom, generally designated by :the numeral l0,is zmounted by means of a .tubular base standard Il on the platform i12.of .a motor vehicle truck |13. A Icylindrical post M is revolublyYmounted within member Il, and is also vertically supported thereby, .byany suitable arrangements conventional in the art. The upper end '.ofpost I4 has a pair of spaced rearwardly projecting mounting brackets I5,between which is mounted, on a horizontal axle i6, amounting structurel1 Afor lthe rearward end of the, boom. This mounting structure I'lcomprises a pair of .side :plates i8 connected by a transverse box.structure v20 (Figure 2) in which a rearward mounting tube 2l `of theAboom is firmly seated. The forward portions ofthe side plates I8 haveinwardly bent ilange portions 22 which engage and are welded tothe tube2l, all as may be clearly understood from Figures 1 and 2. The tube 2iis thus rigidly mounted between the side plates I3 of the mountingstructure I1.

The upper end of post I4 also has` a pair of spaced forwardly projectingbrackets 24, the forward ends of which have any suitable arrangementsfor supporting the underside of the tube 2l in a vertically adjustablemanner. A suitable device for this purpose is completely illustrated inmy prior Patent No. 2,571,858. As here indicated, such a device maycomprise a jack screw 25 swivelled to the bottom of the tube 2 I, asindicated at 26, the bracket arms 24 carrying a, nut member, not shown,which surrounds the lead screw 25, and which may be rotated, forexample, by a gear 21 connected thereto, and a hand crank 28 forrotating gear 21 through any suitable mechanism to effect axialtranslation of the lead screw. These arrangements form no part of thepresent invention, and are therefore not further detailed herein.Reference to Patent No. 2,571,- 858 is made for the details of such adevice. Suiiice it to say that by this arrangement, the boom III may beelevated or depressed about horizontal axle I6.

The boom comprises a plurality of telescopingr tubes, the larger tube 30(Figures 1 and 6) having its rearward end portion enclosed within themounting tube 2 I. As shown, the tube 3B engages the tube 2| at thebottom, but is of somewhat smaller diameter than the tube 2 I, leaving aspace 3| along the top. A filler block 32 lls the space between the tube30 and the tube 2I at the rearward end of the assembly, and is welded inplace, as indicated. The forward end of the tube 2l is turned inwardlyand shrunk to the tube 35, as indicated at 33. Thus the rearward endportion of the tube 36 is xedly mounted inside the tube 2l, the tube 33being thereby adequately supported for a substantial distance out fromits rearward extremity.

Telescopically received inside the first tube 38 of the telescopic boomis a second tube 34, and telescopically received in the tube 34 is athird tube 35, while telescopically received in tube 35 is a fourth tube36. As will be seen, the reduction in diameter from tube to tube issufcient to leave clearance spaces between successive tubes. As shown,the lower sides of tubes 34, 35 and 36 are positioned adjacent the lowersides of tubes 3U, 34 and 35, respectively, leaving cable channels 31,38 and 39, respectively, at the top. At the rearward ends of thetelescopic tubes or boom sections 34, 35 and 36 are spacing collars 4B,4| and 42, respectively, welded to the correspending tubes, anddimensioned to be receivable with a free sliding t inside the tubes 30,34 and 35, respectively. It will be seen that the collars 40, 4I and 42consist of spacers to position the corresponding telescopic tubes of theboom in eccentric positions with respect to the next larger tubes inwhich they are disposed, to assure maintenance of the described cablechannel clearance spaces 31, 38 and 39; also that the upper surfaces ofthese collars have slide bearing on the inner upper surfaces of thesurrounding tubes. Each tube of the boom exerts an upward thrust on thenext larger tube through its described collar, and exerts a downwardthrust on the next larger tube near the outer end of the latter. Toreceive this downward thrust, each tube is accordingly The forward endof the outermost tube @E Qfvv L 4 the boom carries a hooded support 55for a pulley 55 in alinement with the hollow space inside the boom, anda cable 51 extending through the boom passes over this pulley 56 andcarries a suitable implement such as a hook'58 at its end. At therearward end portion of the boom, this cable 51 is wound on a windingdrum 59, here shown as operable through a suitable gear train, generallydesignated at 59a. (Figure 2), from a hand crank on a shaft 62projecting through one of the side plates I8.

Consideration will now be given to the means for extending the rstextensible tube 34 from the lowermost tube 3U. A fairly heavy cable isemployed, doubled to form two halves, connected by a bight, the two endsbeing wound on a winch 6B (Figure 2) mounted between side plates I8.This winch has two winding drum sections 65a and 60h, separated by adisk 63o. The two ends of the cable are fastened on opposite sides ofthe disk 60e, and separately wound on the two drum sections 60a and 60h,thus preventing in terference with one another and assuring properlwinding and unwinding of the two end portions of the cable. The winch 60has at one end a gear 6I, with which meshes a small spur gear Gla on ashaft 63, and a larger gear 64 on said shaft is driven through smallspur gear 65 from a shaft 66. Shaft 66 may be driven through pulley 61from an electric motor (not shown) mounted on the structure I1, or maybe driven by means of a crank such as 68 engageable with the protrudingend of either shaft 66 or shaft 63. It will be evident that when thecrank is engaged with the shaft 66, the manual drive will be at muchlower gear ratio than when the crank is engaged with the shaft 63. Forheavy work, such as this boom is particularly designed to handle, it isusually preferable to employ the motor drive.

Two cable flights 1I) and 1I extend from the two cable ends wound ondrum 60 in a forward or outward direction over tube 3U to a pair ofclose spaced pulleys 12 and 13, respectively (Figure 3), mounted forrotation on a shaft 14 within a box structure 15 welded to the top sideof the tube 3i! near the forward or outer end of the latter, the pulleysbeing separated by a spacer 14a. 'I'he box structure 15 includes sideplates 16, in which the pulley shaft 14 is mounted, and a top plate 11.The two pulleys 12 and '13 receive between them a longitudinal key 50 onthe top side of boom section 34 (Figure 3) to constrain section 34against rotation. The key 50 does not show in Figure 6 because the planeof said figure is taken just behind said key.

The top side of the tube 30 is apertured opposite the pulleys 'I2 and13, as indicated at 80 in Figures 4 and 6, and the lower portions of thepulleys are received in this aperture, and are so positioned that thetwo flights 10a and 1Ia of the cable running off the lower sides of thepulleys (understood to follow the nights 'I0 and 1I, respectively) areguided into the channel space 31 between the top inner side of the tube30 and the top outer side of the tube 34. These two cable flights 10aand 'IIa extend rearwardly in the cable channel space 31 in substantialparallelism to a pair of pulleys 84 and 85, respectively, mounted bymeans of angularly disposed brackets 86 welded to the rearward face ofthe:

collar 4I] on the rearward end of the tube 34; The cable flights 10a and1Ia are passed rear-f wardly through holes 81 in the upper portion'of6911er 40 (see Figure 9 The, pulleys 84 and.

are so positioned between bracket llili as to re ceive the end portionsof the two cable vflights .10a and la from these holes '81 and :t0return the cable as forward-ly reaching .flights 'ich and 1lb, whichpass through other holes 8.3 (Figure 6) positioned outwardly towards thetwo sides of .the collar. Figures -6 and '9 illustrate how the vbrackets'8.6 position the pulleys 8e and 85 vin angular relationship :to guidethe cable asdescribed.

'The forwardly reaching lcable nights lub and Hb pass out of the forwardend of the tube 3i! around grooved half-round guides sil and 19|disposed in vertical planes and mounted in housings 82 welded to`opposite Isides .of vthe forward end of the :pipe '30. As Aclearlyillustrated, the guides 90. and .9| receive the forwardlyyreachingncable flights 10b and llb, the portions lc and '71o of thecable returned by these guides forming the bight 95 at the mid point ofthe doubled cable. This bight is looped around the aforementioned pulleyhousing l .and is received and supported by a grooved vequalizing guideSii welded to the rearward side of the housing l5 at a level just abovethe .top Aside vof the .tube section 3B. VThis guide .85 -is `formedwith groove 91 to receive the cable, and its two lwings are arcuatelyformed at the extremities and positioned in line with the topends of theguides all and V9 l.

In operation, winding `'up of the :two end portionsof the cable onlwinch '3B results Ain shortening the cable loops engaged with thepulleys B4 and 85, thereby extending .the tube 34 from the tube 33.Stresses in the two halves `of .the cable will be equal because of thelooping or its 'bight around the equalizing member .93. lf at the start.one of the two halves ofthe `doubled cable should be longer than theother, the shorter Ais placed under :greater tension, and .thecableshifts around the equalizing member 93 until .the two cable halvesare vof the same length .and .bear equal shares of the total load.

Tube 35 has at .the top a key 9.8, which :is fre-- ceved ina guide 99inside the tube 34 to pre' vent rota-tionof tube 35.

For the 4purpose of extending the `tube 535 from the tube Y34, a cableHill is employed, the two .end portions .of which are clamped voranchored by a clamping means |112 mounted to the rear of the pulley-housing l5, as shown .in Figures 4, 6 `and 13. A double grooved guidemember |05 .is mounted on .the rear fof the housing member .15, justabove the yequalizing member 3.6. A clamp plate It grooved in `oppositesides is welded to and 'eX-tends rearwardly from the center .of guide|05, and the :clamping means z||l2 .is completed :by clamp 'blocksVILE-i :and suitable screws. The two ends of the cable '|353 are thusclamped to the plate IE5 .by clamp .blocks '191. As here shown, plate|95 interrupts the .upper groove of .guide |05 at the center, :but notthe lower groove thereof, since :the .cable is to run :entirely :aroundthe lower groove. Two nights 'Mil .and .of this cable G .extend from theclamped cable ends around the upper grooves 'in opposite .sides of theguide member |165, .passing lto opposite sides Aof the pulley housing.l5 and going onto the inner grooves `of fdoubly grooved .pulleys :HL2(Figure 7) mounted in pulley yhousings ||3 welded to the top of tube 34near .the forward or outer end of the latter. The housing members ||3are spaced apart and positioned in angular planes as indicated in Figure7, so that the upper sides of the pulleys are positioned to receive thecable flights ||0 and leading forwardly from the `two .ends vof guidemember m5. The 'lower portions of these pulleys project throughapertures v| lila in the tube 34, so as :to guide the cable into thecable channel space r38 between ,the tubes 34 and 35, in the mannerclearly .shown in the drawings. The nights and ||s8 running olf theunder sides .of the .inner .grooves of these pulleys .|:|2 .are thusguided into the cable channel space .38, and .continue rearwardlytherein to "be looped around grooved half-round guides .mounted on theupper portion `of collar 4| at the inner end of the tube 35, suitablerapertures |255 being provided in the collar 42| to pass the cables(Figures 10 .and 12). 'The cable flights il? and :H8 are continued,beyond the guides 25, by forwardly reaching flights |22 and |23,respectively. 'These latter run onto the undersides of the outer groovesof the previously mentioned pulleys H2, becoming return flights |24 and1.28 extending rearwardly from the tops 'of pulleys ,I l2. These returnflights lead around opposite sides of pulley housing 715 to oppositeends of the lower groove of guide |85, forming a central loop or bight|21? around this grooveat the mid point of thecable.

Now, when tube 31| is extended from tube 30 as aforesaid, .the cab-leloops or bights around'the guides |25 .at the inner ends of the tube 35are necessarily shortened, causing extension of tube 35 from tube 34.All flights of the cable will necessarily equalize their share of ltheload, because of the provision of feq-ualizing guides |25 and thecontinuous lower groove of the guide |05, about which the centralunanchored cable loop iis can adjust itself to equalize any diiferencein tension between the multiple nights of the cable.

The tube 13S is extended from the tube 35 in a precisely similar mannerusing a cable |35 whose two .ends are anchored .at |32, and which isarranged about a guide member .|3"i like the guide member |115, doublygrooved pulleys |38 and |39, and half-round guides |412 .on collar 42 atthe inner end of tube 3.5, in the same way as the cable Ina is strungabout guide H35, Vthe doubly grooved pulleys |112, and the guides |25,the only difference being .that the pulleys |58 and '|33 are mounted ata wider V-angle than the pulleys |12, so as to keep the cables clear ofone another.

It will .be seen that I have provided multiple cable arrangements forextending the telescoping tubes or" the boom, and have arranged allcables to equalize the load between their `several nights, so that .theload will be equally shared and-no one cable night-subjected tooverstrain while another flight remains slightly slack; The boom as thusdescribed is well adapted for carrying heavy loads, .considerablyheavier than could be imposed with any arrangement employing singlecables. As mentioned in the introductory part of the speoiilcation,there is .a vlin'i'itation upon Ithe size of .cable which can Abe easilyused in such an apparatus as the present. 'When `that limit is reached,further increase in carrying capacity can "be .achieved only bymultiplied cable arrangements, andthe multiple cable arrangementprovided by the present `invention assures greatly increased loadcapacity, without liability of unduly straining a given cable flight 1inthe multii plied arrangement.

nFigures '14 and l5 I `have shown, somewhat diagrammatically, a modiedcable and pulley arrangement for extending the tube 34 from the tube3|). Here, two halves |48 and |49 of a single doubled cable pass overindividual pulleys and mounted on the outer end of outside tube 30,thence rearwardly between the tubes 30 and 34, through holes, such asindicated at |52 and |52', in collar 40a, around pulleys |53 and |54individually rotatable in a housing |55 mounted on collar 40a, thenceforwardly through holes |55 and |51 to the forward end of tube 30, thebight of the cable being passed around a half-round equalizing guide |58mounted on the forward end of tube 35. It will be appreciated that thisarrangement is equivalent in operation to that first described, but issomewhat simpler in structure, and shorter in overall cable length. Theload is again distributed equally between the two strands |48 and |49 ofthe single cable.

The drawings and description will be understood as merely illustrativeof one present embodiment cf the invention, and it will be understoodthat various changes in design, structure and arrangement may be madewithout departing from the spirit and scope of the invention or of theappended claims.

I claim:

l. A hoisting boom structure comprising at least two telescoping tubes,a first of which is adapted for pivotal mounting on a base member, and asecond of which is telescopically received within the first tube, saidsecond tube being sufnciently smaller than said first tube to leave aclearance space therebetween, a spacer on the inner end portion of saidsecond tube bearing on the inside of the first tube and positioning saidtubes with a cable channel space therebetween extending longitudinallyfrom said spacer to the forward end portion of the nrst tube, and meansfor extending the second tube from the first tube including a doubledcable having a bight, an equalizing guide on the forward end portion ofthe first tube around which the bight of said cable is looped andarranged for tension adjustment movement thereabout, guides mounted atthe forward end of said nrst tube for taking the two cable nightsextending forwardly from said equalizing guide and turning themrearwardly into the cable channel space between the nrst and secondtubes, pulleys mounted on the rearward end portion of the second tubearound which the cable nights from said guides are looped and extendedforwardly in said cable channel space, and pulleys mounted on theforward end portion of the nrst tube around which the forwardlyextending cable flights returning from the last mentioned pulleys arelooped and extended rearwardly outside the boom structure, and windingdrum means for taking up and paying out the two cable flights extendingrearwardly outside the boom structure.

2. A hoisting boom structure comprising at least two telesooping tubes,a, nrst of which is adapted for pivotal mounting on a base member, and asecond of which is telescopically received within the nrst tube, saidsecond tube being sufficiently smaller than said first tube to leave aclearance space therebetween, a spacer on the inner end portion of saidsecond tube having bearing on the inside of the nrst tube andpositioning said tubes with a cable channel space therebetween extendinglongitudinally from said spacer to the forward end portion of the nrsttube, and means for extending the second tube from the nrst tubeincluding a doubled cable having a bight, an equalizing guide on theforward end portion of the nrst tube around which the bight of saidcable is looped and arranged for tension adjustment movement thereabout,the two cable nights from said bight being arranged to extend rearwardlythrough the cable channel space between the first mentioned tube and thesecond mentioned tube, pulleys mounted on the rearward end portion ofthe second tube around which the cable nights from said bight are loopedand extended forwardly in said cable channel space, and pulleys mountedon the forward end portion of the nrst mentioned tube around which theforwardly extending cable nights returning from the last mentionedpulleys are looped and extended rearwardly outside the boom structure,and winding drum means for taking up and paying out the two cable nightsextending rearwardly outside the boom structure.

3. The subject matter of claim 2, wherein said winding drum meanscomprises two separated drum sections for the two cable flights.

4. The subject matter of claim 2, wherein said equalizing guidecomprises a forwardly facing guide element mounted on the forward end ofthe nrst tube in alinement with the cable channel space between thefirst and second tubes.

5. The subject matter of claim 2, wherein said equalizing guidecomprises a rearwardly facing guide element mounted on the outside ofthe nrst tube near the forward end thereof, and including guides on theforward end of the first tube for guiding the cable portions extendingfrom said equalizing guide into the cable channel space between the nrstand second tubes.

6. In a hoisting boom structure including at least three telescopingtubes, a lfirst of which telescopically receives a second thereof, and athird of which is telescopically received in said second tube, saidthird tube being sufficiently smaller than said second tube to leave acable channel space therebetween, and means for extending the secondtube from the nrst tube, the combination with said structure of: meansfor extending the third tube from the second tube during and by virtueof extension of the second tube from the first tube including a cablehaving two ends and a bight, securing means securing the two ends ofsaid cable to the nrst tube, pulleys for said cable on the forward endportion of the second tube, said pulleys receiving nights of said cablereaching forwardly from said secured ends and being positioned to turnsaid cable nights into alinement with the cable channel space betweenthe second and third tubes, the cable portions so turned into alinementwith said cable channel space forming two nights extending rearwardly insaid space, guides on the rearward end portionsof said third tube aroundwhich the last mentioned cable nights are looped to form two forwardlyreaching cable nights, pulleys on the forward end portion of said secondtube receiving said last mentioned cable nights and turning the cableportions rearwardly to form two nnal rearwardly extending nights whichterminate in said bight, and an equalizing guide on said first tubeabout which said bight is looped for anchorage and tension adjustmentmovement.

No references cited.

